Infrared magneto-polaritons in MoTe$_2$ mono- and bilayers

TL;DR

This study demonstrates the formation of infrared exciton-polaritons in MoTe$_2$ monolayers and bilayers within a micro-cavity, revealing enhanced light-matter interactions and spin-valley locking effects relevant for quantum optoelectronics.

Contribution

It provides the first joint experimental-theoretical evidence of exciton-polaritons in MoTe$_2$ monolayers and bilayers, highlighting their distinct relaxation dynamics and spin-valley properties.

Findings

38% increase in Rabi-splitting for bilayers

Enhanced polariton relaxation in bilayers

Observation of spin-valley and spin-layer locking via Zeeman effect

Abstract

MoTe$_2$ monolayers and bilayers are unique within the family of van-der-Waals materials since they pave the way towards atomically thin infrared light-matter quantum interfaces, potentially reaching the important telecommunication windows. Here, we report emergent exciton-polaritons based on MoTe$_2$ monolayer and bilayer in a low-temperature open micro-cavity in a joint experiment-theory study. Our experiments clearly evidence both the enhanced oscillator strength and enhanced luminescence of MoTe$_2$ bilayers, signified by a 38 \% increase of the Rabi-splitting and a strongly enhanced relaxation of polaritons to low-energy states. The latter is distinct from polaritons in MoTe$_2$ monolayers, which feature a bottleneck-like relaxation inhibition. Both the polaritonic spin-valley locking in monolayers and the spin-layer locking in bilayers are revealed via the Zeeman effect, which we map and control via the light-matter composition of our polaritonic resonances.